By employing the latest developed class-D amplifier devices,
power MOS-FET achieves ideal highly accurate current switching in the
power stage, and high-voltage gate driver IC with excellent time-axis
control maximizes the ultimate PWM switching. The exceptional
performance of the class-D devices ensures ultimate real-sound with
quality damping in the mid to low ranges even when driving
low-efficiency speakers. Furthermore, the sweet and rich tonal character
in the mid to high ranges of the amplifier is almost like the tone of
the best triode tube amplifiers.

In order to maximize the potential of the unprecedented high
performance of this amplifier (power utilization in the power stage at
maximum output; 96%), we daringly employed a classical and very simple
plus/minus power source composed of minimal numbers of high quality
components, such as only transformers, bridge-diodes and capacitors.

Specially selected parts of low-pass filter contribute to the Real-Sound

The sound of this class-D amplifier owes a lot to the
individual parts of low-pass filter in the final stage of the amplifier.
The capacitor and the coil employed for the low-pass filter were
custom-ordered after careful listening tests and guarantee the excellent
musical sound of RSA-F33EX / RSA-M3EX / RSA-V1EX. Above all, many
custom hermetic seal paper-oil filled capacitors are employed in the
low-pass filter and snubber circuit of RSA-F33EX because of the natural
and vivid character of the sound only those old type capacitors have.
These paper-oil filed capacitors have been supplied to the aerospace
industry for the past half century and made to meet the strict MIL
standards for getting the highest reliability.

In an unusual endeavor for an audio amplifier, natural wood was used for the base chassis and insulators.
Base-chassis of RSA-F33EX: A solid laminated panel of European
spruce from Austria was used for the under-base. Spruce has long been
used for the top plate of stringed instruments and the soundboard of
pianos, and is known as a material with excellent sound quality that
provides quick vibration trans-mission and moderate damping.
The combination of this material with the rigid steel chassis produces a rich pleasant sound.
Insulators of RSA-F33:Three insulators combine pure painted
maple from Hokkaido, Japan and hickory from North America. Maple has
excellent strength and is used in combination with spruce for the sides
and backs of stringed instruments. Hickory is a hard material that
absorbs impact well and is used for drumsticks for example. The maple
and hickory insulators moderate the vibrancy of the spruce material and
help provide rich musicality.

RSA-F33EX

RSA-M3EX

RSA-V1EX

Specifications

RSA-F33EX

RSA-M3EX

RSA-V1EX

Amplifier

Maximum output

120 W × 2 (4Ω), 90 W × 2 (6Ω), 60 W × 2 (8Ω)

100 W × 2 (4 Ω), 75 W × 2 (6Ω), 50 W × 2 (8Ω)

Frequency response

10 Hz - 30 kHz ±1dB (6Ω, 1W)

Harmonic distortion ratio

0.02% (at 1 kHz, 80% output)

Input sensitivity, gain

300 mVrms, 37.3 dB (at MAX volume, 6Ω, 1kHz, unbalanced input)

Line input terminals

XLR input: 1 RCA inputs: 3

Speaker terminal

1

Power supply, other

Power voltage

220 V AC, 50 Hz

Electrical consumption

With no signal: 15 W, during maximum output: 215 W (8 Ω, 100 Hz)

With no signal: 15 W, during maximum output: 180 W (8Ω, 100 Hz)

External dimensions

450 mm (width) × 130 mm (height) × 422 mm (depth)

440 mm (width) × 125 mm (height) × 414 mm (depth)

440 mm (width) × 120 mm (height) × 414 mm (depth)

Weight

20 kg

15.5 kg

14.5 kg

Included items

Power cord

1

Operation manual

1

Technology of the top of our lineup the superb “Real-Sound” of RSA-F33EX

The “Real-Sound” is supported by the excellent performance power supply with classical analog design of RSA-F33EX

Rectifier

A newly developed withstand high voltage “ Ultrafast
Soft-recovery” diodes for professional use in RSA-F33EX ensures clear
and transparent but also rich and powerful sound with spacious
atmosphere across the entire range.

Capacitor

The main custom electrolytic capacitor and the high voltage
custom oil filled capacitor for best signal-use in parallel achieve
smooth and beautiful sound over upper and middle range to the ultra-low
range.

The low-pass filter at the final stage
determines the highly sophisticated sound
of RSA-F33EX